196 Volvo 850 T

When I open my gas cap, (when the tank is almost empty), I hear a WOOSHING sound, LIKE AIR IS RUSHING INTO A VACUUM. Is that normal?
Then, here’s the PROBLEM: right after I fill up my gas tank (when it was almost empty), I drive a minute (more or less) and my engine STALLS and SHUTS OFF (as if can’t get enough gas). The ENGINE light comes on. I have to keep restarting it and barely reach home. It stalls in PARK and in GEAR, while I’m driving. A bag smell comes out of the exhaust. Here’s the weird part: when it sits overnight, in the morning I can drive it fine, with no stalling.

It’s happened three or four times. My mechanic did what he called a “MINI-tune-up” and “Perform injection clean” and “Reset system” (charged almost $700) BUT THIS DID NOT FIX THE PROBLEM. When I brought the car back to him, he said he did not know what was wrong with it, but I should bring the car to him when the gas was almost empty so he could fill it and see what happens. So why did he charge me $700 if he didn’t fix what I asked him to fix??
What should I do?

It sounds like something is wrong with the evaporative emissions control system, which collects gas fumes from the gas tank so they don’t escape into the atmosphere. The charcoal canister which collects the fumes and then releases them into the engine to be burned might be saturated with gas, which can happen if you overfill the tank. If so, that could cause the engine to stall or run badly, and the canister woukd have to be replaced. Or one of the solenoid valves that controls the flow of the gas fumes may not be working.

The bad smell also suggests that the evaporative emissions system is the problem.

You may also need a new gas cap, which has a one-way vent to allow air to be sucked into the gas tank as the gas level drops. A hard vacuum in the tank suggests the cap vent may not be working.

Most of all, you need a competent mechanic. This one evidently has no clue if he hasn’t checked out the evaporative emissions system. Use the “Mechanics Files” section of this site to find a recommended mechanic in your area, preferably a Volvo specialist. You could also try a dealer.


Since the check engine light was on, there will be codes

Did the mechanic attempt to retrieve any stored or active fault codes?

The fault code won’t have all the answers, but it can be helpful, as far as diagnosis goes

There was a recall a few years ago on the gas tank for this issue. Did you take it in?

Mechanic soaked you for a bunch of unneeded crap that was in noway going to fix your car. This is and evaporative system problem and he is working on fuel and spark. Find a new mechanic. Post codes.